Beverage cans may be filled by automated container filling systems, wherein an empty can or other container is engaged with a filling valve, and the beverage dispenses from the filling valve into the can. One automated container filling system provides counterpressure filling, in which the can is filled with pressurized gas before the beverage is dispensed. In one counterpressure filling system, a filling valve includes a seal that expands against the top of the can, thereby sealing the inside of the can for containing pressurized gas.
In general, a plurality of cans move through a rotary filler. Empty cans are presented to the filling valve as the rotary filler turns. After the filling valve fills the can, the can moves off of the rotary filler. In valves associated with known machines, various deficiencies are found to effective and fast filling procedures. One problem noted with known valves relates to the liquid seal within the valve, which has a wedge-shaped sealing surface which contacts a wedge seal seat, wherein the liquid seal has the tendency to be frictionally engaged in a manner that causes hesitation when opening the valve, thereby causing a short fill. Further, the liquid seal seat formed in such known valves has been formed integral with the valve body, so that it is not replaceable apart from the entire valve. A further impediment to achieving desired fill time with the known valve relates to the use of a screen positioned just beneath the sealing surface to assist in stopping flow of the liquid upon valve shutoff. The position of the screen is well above the valve outlet, allowing a significant amount of liquid to continue to drip from the valve after closure, and causing delay in completion of the fill. Other delays in the filling process are found in the need to snift a significant volume of gas upon completion of the fill from the headspace in the valve. Loss of liquid contents also could occur by the liquid entering the space around a can sealing member during the fill process, and being retained in association with the valve behind the can sealing member. Additional problems with known valves are found in the manner in which liquid is directed into the can or other container. With a can, known valves direct the liquid in a spiral fashion, but introduce the liquid in a direction which is well below the top of the can. This can cause disruption in the flow of the liquid into the container as the fill height increases.
Another problem with prior valves has been their ability to fill containers in a manner to reduce foaming or for filling containers of differing sizes. For example, as it is desired to fill the container as quickly as possible, introduction of the liquid is performed with the valve fully opened, which can result in excessive foaming. Further, a valve for filling a small can may cause foaming and/or excessive fill times when used for filling a large can and vice versa. This causes lost product, or inaccurate filling, or lost production due to change-over from one valve to another to accommodate various containers. Other problems, including limitations to proper cleaning of such valves, and others, have been noted.